Police say a man held up a bank on Parrish Street in Durham and then held up another on Chapel Hill Boulevard Wednesday.
On Thursday, Durham police said he tried to rob the State Employees Credit Union on Ben Franklin Boulevard, but he didn't get away with any cash.
So 20 minutes later, the man robbed the Research Triangle Park Federal Credit Union in RTP.
Surveillance photos of Thursday's heist in RTP and the robbery on Tuesday have been released. In each case, the suspect was wearing a baseball cap.
The Durham County sheriff's office says the same man is responsible for all four crimes.